The California high-speed rail project is now rapidly approaching an intersection controlled by a powerful, but usually low-profile federal board.

Behind the scenes, high-level advocates and skeptics alike have been lobbying the three-member Surface Transportation Board. The board already disappointed high-speed rail supporters by concluding it has legal jurisdiction over the in-state project.

Now, wading through an unusually high volume of comments, the board is being asked to decide by June 17 whether to exempt the first phase of the California project from federal approval requirements. The crucial first phase spans 65 miles, from Fresno to Merced, and has attracted considerable attention.

"It isn't often that the board is contacted by so many senators and representatives of districts in one state that could be impacted by a proposal before the board," board vice-chairman Ann D. Begeman noted on May 20.

The three presidentially appointed Surface Transportation Board members oversee rates, construction, mergers and other rail-related issues. The board can also decide that a construction project or other railroad undertaking is exempt from its oversight.

California High-Speed Rail Authority officials and their supporters have requested such an exemption, arguing that the project has been fully studied and that further waiting to clear more bureaucratic hurdles would be harmful.

"Should the project face a prolonged delay, local businesses impacted by the high-speed rail alignment would be faced with great uncertainty," Fresno Mayor Ashley Swearengin wrote the federal board last month.

California Gov. Jerry Brown, likewise, urged the board to exempt the project that he called "consistent with the nation's rail transportation policy," while Rep. Jim Costa, D-Fresno, joined several other House Democrats in declaring that "unnecessarily delaying this project will be yet another hit to the regional economy."

But since late February, when Rep. Jeff Denham, R-Turlock, first wrote the federal board urging it to take a look at the California project, skeptics have been weighing in as well. Denham chairs the House railroad subcommittee.

"We urge the (board) to slow the madness down and insist the (state rail) authority thoroughly address the safety and legal concerns raised to date," Kings County supervisors wrote.

The final decision will be made by people who aren't usually in the public eye.

Begeman formerly worked as a top staffer for Republican Sen. John McCain of Arizona. Citing the "scope of the project and significant public interest," Begeman in her May 20 statement indicated she'd like the board to "fully analyze" the California proposal. She sided with project skeptics in urging a longer public comment period. Overall, she appeared to be inclined to reject California's request to exempt the project from board oversight

"In my view, continued regulation by the board is necessary here," Begeman declared in an April 18 statement.

The board chairman, Daniel R. Elliott III, formerly practiced as an attorney for the United Transportation Union, an Ohio-based organization that represents railroad workers. The third member, Francis P. Mulvey, is an economist with an undergraduate degree from the University of California at Berkeley and a doctorate from Washington State University. He formerly served as a Democratic staffer on the House railroad subcommittee.

Neither Elliott nor Mulvey have clearly tipped their hands concerning the California project in publicly available statements or writings. Because it's an ongoing application, no board member would comment on it Friday.

But in a potentially illuminating case that split the board last December, Mulvey opined that Florida's high-speed rail project should be federally regulated.

"If a proposed rail line uses facilities that are in the general system of rail transportation and is related to the movement of passengers in interstate commerce, Congress has determined that the board should regulate its proposed construction," Mulvey wrote.

The other two board members thought otherwise, and in a 2-1 decision on Dec. 12, 2012, the board opted to exempt from its oversight a 230-mile high-speed segment planned for between Miami and Orlando.

"Construction and operation of the proposed line would not be part of the interstate rail network and therefore would not come within the board's jurisdiction," the majority concluded.

In the California case, the three board members will each draft their respective opinions and then reconcile them. If no exemption is granted, the high-speed rail authority would have to submit a full application to the board before construction begins.